Elastomeric Networks, and Their Use in Novel Nanocomposites and Related Materials

技术概述：该研究的一个实际目标是获得结构-性能关系，可用于优化弹性体材料的性能。实验将包括各种变形，并进行相应的计算机模拟。弹性体将包括商业上重要的聚合物，通过各种技术交联。一个具体项目将是生产具有增强定向和改进机械性能的可生物降解弹性体凝胶。另一个例子涉及表征应变诱导结晶，这可以大大改善材料的机械性能。新型增强填料如二氧化硅将在原地生成，产生不寻常的颗粒形状和方向，一种类型的陶瓷颗粒将被另一种类型的陶瓷涂层。还可以通过增强沸石来编织弹性链，以获得其他不寻常的性能。模拟还将用于阐明填充弹性体的增强机制，这是聚合物科学领域尚未解决的主要问题之一。这里特别令人感兴趣的是，当初级颗粒结合成相对稳定的结构（称为“聚集体”）和不太稳定的排列（称为“团聚体”）时，所获得的增强的类型和程度。最后，将进行实验，以利用弹性畴提高陶瓷为连续相的聚合物-陶瓷杂化复合材料的抗冲击性。在这方面特别令人感兴趣的是通过在一个相中使用网络结构的连通性来“挫败”不同双组分系统中通常类型的相分离来控制色散水平。非技术总结：所描述的工作将提供一个更好的理解聚合物，特别是弹性体和纳米复合材料。这将最终为制备和利用更好的弹性体材料和各种类型的复合材料提供重要的指导。结果将以通常的方式在期刊出版物和各种科学或工程学会的全国会议上的演讲中传播。更广泛的影响将包括整合研究和教学。弹性体材料所表现出的橡胶般的弹性是其最显著的特征之一，申请人将继续在讲座演示、实验课程实验和标准物理化学概念的修改中利用这一点。在这些项目中获得的实验、模拟和理论结果将继续包括在辛辛那提大学教授的弹性课程中，以及申请人自1972年以来教授的一些美国化学学会短期课程中。

TECHNICAL SUMMARY:One practical goal of the research being carried out is to obtain structure-property relationships that can be used to optimize the properties of elastomeric materials. Experiments will include a variety of deformations, and corresponding computer simulations will be carried out as well. Elastomers will include commercially important polymers, cross linked by a variety of techniques. One specific project will be producing biodegradable elastomeric gels of enhanced orientation and improved mechanical properties. Another example involves characterization of strain-induced crystallization, which can greatly improve the mechanical properties of a material. Novel reinforcing fillers such as silica will be generated in-situ, yielding unusual particle shapes and orientations, and ceramic particles of one type will be coated by a ceramic of another type. It will also be possible to thread elastomeric chains through reinforcing zeolites, to obtain other unusual properties. Simulations will also be carried out to elucidate reinforcing mechanisms in filled elastomers in general, which is one of the major unsolved problems in this area of polymer science. Of particular interest here is the types and extents of reinforcement obtained when the primary particles are bonded into relatively stable structures called "aggregates" and into less-stable arrangements called "agglomerates". As a final topic, experiments will be carried out to exploit the ability of elastomeric domains to improve the impact resistances of polymer-ceramic hybrid composites in which the ceramic is the continuous phase. Of particular interest in this regard is control of the level of dispersion by using the connectivity of network structures in one of the phases to "frustrate" the usual types of phase separation in disparate two-component systems. NON-TECHNICAL SUMMARY:The work described will provide a better understanding of polymers in general and elastomers and nanocomposites in particular. This will ultimately lead to guidance important for the preparation and utilization of better elastomeric materials and various types of composites. Results will be disseminated in the usual way, in journal publications and lecture presentations at National Meetings of various scientific or engineering societies. Broader impacts, would include integrating research and teaching. The rubberlike elasticity exhibited by elastomeric materials is one of their most striking features, and the applicant will continue to exploit this in demonstrations during lectures, experiments in laboratory courses, and in the modification of standard physical chemistry concepts. Results from experiments, simulations, and theory obtained in these projects will continue to be included in the elasticity course taught at the University of Cincinnati, and in some of the American Chemical Society Short Courses the applicant has taught since 1972.